The present invention relates to an electronic device, and in particular to an electronic device having a 3-dimensional antenna structure.
Traditionally, portable computing devices have been connected to network through a cable and a LAN card. However, as wireless capability becomes more popular, wireless LAN cards with PCMCIA (Personal Computer Memory Card International Association) interface or CF (compact flash) interface are growing in use. Based on the specifications of the PCMCIA and CF cards, only limited space therein is available to accommodate an antenna with appropriate volume and uniform radiation field intensity.
In various structures, the inverted-F antenna has advantages to recommend use with a compact LAN card.
The radiation mechanism of the inverted-F antenna possesses high flexibility in antenna design, and the radiation field and polarization can be more uniform.
When wireless PCMCIA or CF LAN cards are used, the radiation energy of the antenna in the limited space will decay or be reflected by other metal or plastic elements therein. Reflection distorts the radiation field pattern and decay reduces the overall efficiency of the antenna.
A CF card with inverted-F antenna is disclosed in U.S. Pat. Nos. 6,259,409, 6,348,893, 6,437,745 and 6,545,643, which disclose a planar inverted-F antenna on the antenna plane of a card. Moreover, Taiwan patent No. 520,583 discloses a planar inverted-F antenna formed on a printed circuit board and applied to a wireless LAN card for a notebook computer. However, the disclosed antenna structure requires insertion into the electronic device with the wireless LAN card in operation, such that the radiation energy of the antenna decays or is reflected by other elements of the electronic device, reducing efficiency. Additionally, the radiation field pattern and polarization of the planar inverted-F antenna cannot be regulated.